Who said "I have learned that ruling alone is impossible."?

This quote is attributed to Daenerys Targaryen.

I have learned that ruling alone is impossible. - Daenerys Targaryen

"I have learned that ruling alone is impossible."

Daenerys Targaryen Leadership

"I am the blood of Old Valyria. I am the dragon."

"A dragon is not a slave."

"I will take what is mine with fire and blood."

"The night is dark and full of terrors, but so is the day."

"A leader must be fair and just."

"Integrity is everything."

"One must take responsibility for one's environment."

"In this house, I make the decisions"